On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeD. Appleton, 1909 - 430 páginas |
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Página 114
... the six new species descended from ( I ) , and the eight descended from ( A ) , will have to be ranked as very distinct genera , or even as distinct sub - families . Thus it is , as I believe , that two 114 NATURAL SELECTION.
... the six new species descended from ( I ) , and the eight descended from ( A ) , will have to be ranked as very distinct genera , or even as distinct sub - families . Thus it is , as I believe , that two 114 NATURAL SELECTION.
Página 115
... families , or genera , with those now living , yet are often , in some degree , intermediate in character between existing groups ; and we can understand this fact , for the extinct species lived at very ancient epochs when the ...
... families , or genera , with those now living , yet are often , in some degree , intermediate in character between existing groups ; and we can understand this fact , for the extinct species lived at very ancient epochs when the ...
Página 116
... families , or even orders , according to the amount of divergent modification supposed to be represented in the diagram . And the two new families , or orders , will have descended from two species of the original genus ; and these two ...
... families , or even orders , according to the amount of divergent modification supposed to be represented in the diagram . And the two new families , or orders , will have descended from two species of the original genus ; and these two ...
Página 117
... families , orders , and classes , as at the present day . On the degree to which Organisation tends to advance.— Natural selection acts , as we have seen , exclusively by the preservation and accumulation of variations , which are ...
... families , orders , and classes , as at the present day . On the degree to which Organisation tends to advance.— Natural selection acts , as we have seen , exclusively by the preservation and accumulation of variations , which are ...
Página 127
... families , families , orders , sub - classes , and classes . The several subordinate groups in any class cannot be ranked in a single file , but seem rather to be clustered round points , and these round other points , and so on in ...
... families , families , orders , sub - classes , and classes . The several subordinate groups in any class cannot be ranked in a single file , but seem rather to be clustered round points , and these round other points , and so on in ...
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Términos y frases comunes
accumulated adapted affinities allied species America analogous ancient animals appear archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species divergence domestic doubt embryo endemic existing exterminated extinct extremely facts favourable fertilised fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hybrids hybrids produced important increase individuals inhabitants inherited insects instance instincts intercrossing intermediate larvæ laws less living males mammals manner migration modification modified descendants natural selection naturalists nearly nest occasionally offspring organic organisation origin of species perfect pigeons plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary seeds sexual sexual selection Silurian slight sometimes South America sterility structure struggle successive supposed swimbladder tend theory variability variations varieties vary whole widely